Multimodal alexia: Neuropsychological mechanisms and implications for treatment

Abstract

Letter-by-letter (LBL) reading is the phenomenon whereby individuals with acquired alexia decode words by sequential identification of component letters. In cases where letter recognition or letter naming is impaired, however, a LBL reading approach is obviated, resulting in a nearly complete inability to read, or global alexia. In some such cases, a treatment strategy wherein letter tracing is used to provide tactile and/or kinesthetic input has resulted in improved letter identification. In this study, a kinesthetic treatment approach was implemented with an individual who presented with severe alexia in the context of relatively preserved recognition of orally spelled words, and mildly impaired oral/written spelling. Eight weeks of kinesthetic treatment resulted in improved letter identification accuracy and oral reading of trained words; however, the participant remained unable to successfully decode untrained words. Further testing revealed that, in addition to the visual-verbal disconnection that resulted in impaired word reading and letter naming, her limited ability to derive benefit from the kinesthetic strategy was attributable to a disconnection that prevented access to letter names from kinesthetic input. We propose that this kinesthetic-verbal disconnection resulted from damage to the left parietal lobe and underlying white matter, a neuroanatomical feature that is not typically observed in patients with global alexia or classic LBL reading. This unfortunate combination of visual-verbal and kinesthetic-verbal disconnections demonstrated in this individual resulted in a persistent multimodal alexia syndrome that was resistant to behavioral treatment. To our knowledge, this is the first case in which the nature of this form of multimodal alexia has been fully characterized, and our findings provide guidance regarding the requisite cognitive skills and lesion profiles that are likely to be associated with a positive response to tactile/kinesthetic treatment.

Visual feedback of finger writing in a patient with sensory aphasia: a case report and theoretical considerations

“…In usual kinesthetic reading, a patient watches their finger while tracing a letter or character and obtains some benefits from the action, which does not contradict previous and current findings that visual feedback of finger movements is important for the facilitative effect of finger writing (Itaguchi et al, 2015(Itaguchi et al, , 2017. While the literature has focused on kinesthetic information related to language as an underlying mechanism of finger action helping patients with pure alexia while reading (Kashiwagi & Kashiwagi, 1989;Kim et al, 2011;Lott et al, 1994;Potagas et al, 2017;Seki et al, 1995), the present results suggest that the visual feedback of the movements might play a certain role in kinesthetic reading. Many studies have suggested that the impact of current visual feedback is so strong that it could invoke automatic motor action (e.g., Brass et al, 2001;Fadiga et al, 1995;Itaguchi & Kaneko, 2018) and alter the sensorimotor coordination established throughout one's life (e.g., Krakauer, 2009).…”

“…Researching the underlying mechanism of finger movements executed intentionally or unintentionally in daily life may have many applications. Trace reading is effective in rehabilitation of patients with alexia (Kashiwagi & Kashiwagi, 1989;Kim et al, 2011;Seki et al, 1995). Seki et al (1995) showed that after a long and intensive practice of kinesthetic reading, a patient with alexia improved his reading and showed generalization to unpracticed characters, even when they were presented very briefly using a tachistoscope (200 ms) that did not allow the patient to trace them, indicating that tracing movements can be internalized.…”

“…The present study also has significant relevance to neuropsychological phenomena. Patients with pure alexia use finger tracing actions as an aid in reading letters, characters, or words that they are otherwise unable to read (Bender et al, 1982;Dejerine, 1891;Goldstein, 1948;Kashiwagi & Kashiwagi, 1989;Kim et al, 2011;Landis et al, 1982;Maher et al, 1998). In Japanese patients with pure alexia, the beneficial effects of finger tracing, especially for kana, have been confirmed regardless of whether the lesion area included the splenium (Seki et al, 1995) or not (Sakurai et al, 2006).…”

The Visual Word Form Area remains in the dominant hemisphere for language in late-onset left occipital lobe epilepsies: A postsurgery analysis of two cases

“…This comprehensive battery is used not only to assess acquired deficits [30,31] but also to detect more subtle developmental language deficits such as developmental dyslexia [32,33].…”

Augmentation of cognitive function in epilepsy

“…Our hypothesis is that the subtypes of memory impairment that result will preferentially respond to specific memory interventions, a notion that is also being addressed in the aphasia treatment literature (Kim et al, 2011). To this end, an emerging method for treating neurologically-induced memory impairment is non-invasive brain stimulation (NIBS), including transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS).…”